DSMC Calculation Of Hypersonic Rarefied Flows And Research Of Aerodynamic Thermal Engineering Method

With the development of science and technology,the form of modern warfare has changed.As the most important strategic weapon,missiles have been demanded more and more.The speed of missiles is getting faster and faster,the trajectory is getting higher and higher,and gradually deviating from the continuous flow field.At this time,the rarefied gas effect become serious,and the continuous flow equation is no longer established,resulting in the failure of classical gas dynamics.The Direct Simulation Monte Carlo(DSMC)method has solved this dilemma well.The DSMC method bypasses the solution of the Boltzmann equation and directly simulates the flow field,which has achieved considerable success.In this paper,the DSMC method is used to calculate and analyze the rarefied flow field.According to the comparison between the friction and heat flow of the plate,combine shape correction and compression correction,a new aerodynamic thermal engineering method of rarefied flow field.is developed to calculate aerodynamic heat of the hypersonic projectile,which provided technical support for the thermal protection of hypersonic projectile.Firstly,study the basic theory of DSMC method,molecular dynamics theory.Describe the structure progress of velocity distribution function and elastic collision.Study and discuss different molecular collision models,briefly introduce the advantages and disadvantages of different models.Lay the foundation for the application of this method.Secondly,the DSMC method is programmed based on the unstructured grid technology.Deeply study the key technologies of the DSMC method,such as molecular search technology,sampling of collision pairs,realization of the collision model,and energy exchange in the collision process.And give out the calculation process of the DSMC method.Next,use the DSMC method to calculate the plate problem of the rarefied flow,and analyze the effects of different heights and different Mach number.Analyze and sum up the friction coefficient of the plate to get the function of local friction coefficient of the plate with different heights and different Mach number.And compared with DSMC calculation resultsFinally,analyze and compare the friction with heat flux density of different flow.It is found that in the case of large Ma,there is a comparative relationship in the rarefied flow.At the same time,use the DSMC calculation program to simulate the flow field of conical busbars with different half-cone angles.Using the idea of “equivalent plate”,give out the correction formula of the friction coefficient of the warhead with different half cone angles.Combined with the comparison of friction and heat flow and the calculation formula of warhead friction,a new aerodynamic thermal engineering algorithm for hypersonic warhead is developed.And compared with DSMC calculation results to confirm the Engineering algorithm...